Michael N. Abdo - 02 Mar 2026 Form 4 Insider Report for COMMUNITY FINANCIAL SYSTEM, INC. (CBU)

Role: EVP and General Counsel
Signature: /s/ Danielle M. Cima, pursuant to a Confirming Statement executed by Michael N. Abdo
Issuer symbol: CBU
Transactions as of: 02 Mar 2026
Net transactions value: $0
Form type: 4
Filing time: 04 Mar 2026, 11:55:00 UTC
Previous filing: 03 Feb 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Abdo Michael N	EVP and General Counsel	C/O COMMUNITY FINANCIAL SYSTEM, INC., 333 BUTTERNUT DRIVE, SYRACUSE	/s/ Danielle M. Cima, pursuant to a Confirming Statement executed by Michael N. Abdo	04 Mar 2026	0001933852

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	CBU	Common Stock	Tax liability		-485	-6.7%	$60.55^*	6,769	02 Mar 2026	Direct	F1
holding	CBU	Common Stock						2,731	02 Mar 2026	By 401(K)	F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Payment of tax liability associated with vesting of restricted stock awards.
F2	The number of shares reported herein were acquired pursuant to Community Financial System, Inc.'s 401(K) Plan and are based on a current plan statement.